Esterification‐coupled extraction of organic acids: Partition enhancement and underlying reaction and distribution equilibria

A novel means of extracting carboxylic acids from aqueous solutions is described which involves the use of a lipolytic enzyme to convert the acid to a more hydrophobic ester. A water-immiscible long-chain alcohol serves both as a reactant in esterifying the acid, and as a solvent for extraction of the ester. The net result is a substantial (4-to 15-fold) increase in the apparent distribution coefficient of the acid; 80%-95% of the extracted acid is in the esterified form. The method is applicable to a variety of alcohols and acids.